A research program is described to develop a novel miniaturized solid-state spectrometer designed for analytical measurements over the combination region of the near infrared spectrum (2.0-2.5 ?m or 4000-5000 cm-1). The objective is to develop a robust spectrometer microsensor that is capable of accurate analytical measurements under non-ideal and uncontrolled ambient conditions outside the laboratory. Progress to date demonstrates the feasibility and utility of this approach for the continuous measurement of glucose in interstitial fluid collected by an ultrafiltration probe implanted subcutaneously in laboratory rats. Improvements in the current spectrometer are identified to achieve a limit of detection of 1 mM for glucose from spectra collected over a one-minute period. The research plan is designed to realize these improvements by enhancing the output of custom-made semiconductor light emitting diodes (LEDs), improving the detectivity of an innovative focal plan array detector system, implementing a companion reference channel, and developing data analysis methods to improve the long-term stability of the calibration model. A new electronic interface is proposed to customize and miniaturize data acquisition. Spectrometer prototypes will be characterized and validated in a series of in vitro and in vivo experiments that include continuous and selective glucose measurements in non-anesthetized, freely moving laboratory rats. At the end of the requested four-year grant period, our objective is to have an optimized near infrared microsensor spectrometer that is ready for evaluation in human trials for the continuous measurement of glucose. PUBLIC HEALTH RELEVANCE A novel glucose sensor is proposed based on an innovative miniaturized, all solid-state near infrared spectrometer that is constructed from a set of customized optoelectronic devices. The overall objective is to measure clinically relevant levels of glucose in one minute under non- laboratory conditions. Analytical properties will be validated in laboratory animals.